Roof support in mines



July 16, 1963 V J. w. SEDDON 3,097,829

ROOF SUPPORT IN MINES Filed Jan. 12, 1960 6 Sheets-Sheet 1 N =1 E INVENTOR JEFFREY w, g ED N W ATTORNEYS July 16, 1963 J. w. SEDDON ROOF SUPPORT IN MINES 6 Sheets-Sheet 2 Filed Jan. 12, 19 0 INVENTOR JEFFREY SEDDON ATTORNEYS July 16, 1963 I w, SEDDQN 3,097,829

I ROOF SUPPORT IN MINES Filed Jan. 12, 1960 6 Sheets-Sheet 3 INVENTOR J'EFFREY W. SEDDON W ATTORNEYS J. W. SEDDON ROOF SUPPORT IN MINES July 16, 1963 6 Sheets-Sheet 4 Filed Jan. 12, 1960 INVENTOR JEFFREY W, SEDDON BY M ATTORNEYS July 16 1963 J, w. SEDDQN 3,097,829

ROOF SUPPORT IN MINES Filed Jan. 12, 1960 6 Sheets-Sheet 5 \\JO w m 4 I w $5 4 1 R- I v u L! I AT all i 3 39 g "can a I I R d w to O k I v N a J I L i :1 oi? INVENTOR JEFFREY w. SEDDON July 16, 1963 J. w. SEDDON ROOF SUPPORT IN MINES 6 Sheets-Sheet 6 Filed Jan. 12, 19 60 INVENTOR JEFFREY M SEDDON BY W ATTORNEYS United States Patent Britain Filed Jan. 12, 1960, Ser. No. 1,989 Claims priority, application Great Britain Jan. 16, 1959 7 Claims. (Cl. 262-1) This invention is for improvements in or relating to roof support in mines.

One object of the present invention is to provide a new and improved system or pattern of roof support or timbering in mines which, in a self-advancing or walking support system, combines the advantages of chocks and in-line suports Whilst avoiding the known disadvantages of the latter and in particular ensures that the roof suffers a minimum number of stress reversals.

The self-advancing or walking roof support is one which incorporates means (e.g. hydraulic rarn devices) which enables it to move itself forwardly as stripping or cutting of the coal face proceeds. Generally some at least of such supports are also adapted to push over the coal conveyor to the newly exposed coal face.

According to the present invention there is provided a method or system of operating and setting self-advancing mine roof supports, comprising main supports (e.g. chocks) and at least two rows of intermediate supports, one row in advance of the other, there being a pair of such intermediate supports, one from each row, between each pair of main supports, wherein following each strip or cut the row of intermediate supports which is then rearmost is advanced and the row of intermediate supports which has become the rearmost row remains in this position until after the next strip or cut, the main supports being advanced following each strip or cut.

The expression main support and intermediate support where used in this specification and in the claims is intended to mean two different forms of support, each main support being relatively massive as compared with the intermediate supports and the latter being used in pairs so that the novel and advantageous procedure of operation just set forth can be adopted. One of these advantages is that the support pattern combines the advantages of chocks and in-line supports without the dis advantage of having to withdraw and re-set the in-line supports for each cut. Furthermore, the system or pattern provides three lines of supports with a particularly high concentration of support in the region of the waste edge. The system or pattern is also such as to resist damage or clogging from flushing, i.e. the movement of debris into the chocks or other supports or into the spaces between them, the pattem adopted being such that there is a maximum of freedom of movement afforded around and through the supports.

In certain roof conditions the intermediate supports could have retractable extension bars and after a strip or out has been made the extension bars of the foremost row are extended so as to provide immediate cover under the newly exposed roof.

The invention will be further described, by way of example, with reference to the accompanying drawing wherein:

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FIGURE 1 is a diagrammatic plan view of a portion of a mine working,

FIGURE 2 is a diagram illustrating how, with the method or system according to the present invention, the roof suffers a minimum number of stress reversals,

FIGURE 3 is a sectional elevation of one form of main suport or chock provided for the system according to the invention,

FIGURE 4 is a plan view of FIGURE 3,

FIGURE 5 is a semi-diagrammatic plan view of an intermediate support for use in the system illustrated in FIGURE 1,

FIGURE 6 is a sectional elevation showing in greater detail the construction of the intermediate support shown in FIGURE 5,

FIGURE 7 is a fragmentary detail sectional view of an articulated roof bar incorporated in the supports shown in FIGURES 3 and 5, and

FIGURE 8 is a detail sectional view of a relief and loading valve associated with the roof bar shown in FIGURE 7.

Referring first to FIGURE 1, A indicates the coal face, B the waste edge and C the conveyor by which the coal as it is cut is conveyed away. It will be appreciated that following a cut the conveyor has to be advanced towards the coal face. This is effected as hereinafter described.

. The roof supporting system shown on the drawing comprises main supports or chocks D and two rows of intermediate supports E and F respectively.

The chocks D comprise a base frame, a canopy or headpiece adapted to bear against the roof and three hydraulic props or legs 10. Articulated to the forward portion of each canopy or head-piece is an articulated roof bar or extension 11.

The intermediate supports E and F comprise a base member or foot on which are mounted two hydraulic props or legs 12 which support a roofing bar adapted to be held against the roof. The roofing bar may embody a retractable extension bar 13 but this extension bar may in some cases be omitted.

Incorporated in the chocks D and the intermediate supports E and F are hydraulic ram devices. These ram devices serve to push the conveyor over to the coal face and to advance the chocks and intermediate supports up to the conveyor, as hereinafter described, as cutting of the coal proceeds.

One mode of operating the system or support pattern above described is as follows:

Immediately following the making of a cut all the supports are in the position shown on the left-hand side of FIGURE 1, the extension bars 13, of the supports E, if provided, being temporarily extended so as to afford protection under the newly exposed roof.

Firstly the hydraulic rams in the chocks D are operated to push the conveyor C .over .to the coal face and then the supports F (at the time the rearmost row of supports) are advanced into the position shown on the right-hand side of FIGURE 1. The main chocks D are then drawn forward, by their hydraulic rams, to the position shown on the right-hand side of FIGURE '1. procedure is continued along the whole line of supports until they are all in the position shown on the right-hand side of FIGURE 1.

A further cut is then made following which the above procedure is repeated except that instead of the supports F being moved forward it is the supports E (now the rearmost row) which are moved forward. This procedure of advancing the supports is repeated following each cut, the supports E being advanced following one cut and the supports F following the next cut and so on, the chocks D being advanced at each out.

It will be appreciated from the above description that the support pattern combines the advantages of chocks and in-line supports without the disadvantage of having to withdraw and re-set the in-line supports for each cut.

FIGURE 2 illustrates clearly how the system ensures that the roof suffers a minimum number of stress reversals. In FIGURE 1 three areas X, Y and Z are shown. On initial setting all the supports D and F are under roof X and all the supports E are under roof Y. When the system is advanced supports F move to the position F under roof area Z and supports D are moved to position D under roof area Y, supports E remaining fixed during this advance.

Furthermore, the system or pattern according to the invention provides three lines of supports with a particularly high concentration of support in the region of the waste edge.

The system or pattern above described is also designed to resist damage or clogging from flushing, i.e. the movement of debris into the chocks or other supports or into the spaces between them, the pattern adopted being such that there is a maximum of freedom of movement afforded around and through the supports.

Referring now to FIGURES 3 and 4, the chock illustrated comprises a base 14 and a canopy 15 supported from the base by the three hydraulic props or legs 10 which, when extended serve to secure the chock firmly between floor and roof. The base 14 houses a hydraulic ram 16 for advancing the chock and which may also be used for pushing over the conveyor C.

It is desirable that the chock should have a strengthfiexibility characteristic strong enough to keep the props normal to the roof under uneven floor conditions but with some flexibility to safeguard the chock frame and to return the legs to normal. For this purpose the props are mounted as indicated at 17 so as to provide for limited pivoting on the base 14 and flexible bushes (e.g. of rubber) are provided in the structure as indicated at 18, 19 and 20'.

The roof bars or canopies should be strong enough to cause a prop to bleed before assuming a permanent set. The cantilever bars 11 should also be capable of supporting a concentrated load of say one half ton at the end of the bar but they should be able to give to a limited extent as the roof tends to settle down or otherwise accommodate themselves to the nature of the roof and the load to be supported without becoming distorted. For this purpose the cantilever bar 11 is hinged or articulated to the canopy 15 as indicated at 21 and has an extension or tail-piece 11a which bears against a piston 22 adapted to work in a hydraulic cylinder 23 carried by the canopy 15.

Also mounted on the canopy 15 is a relief and loading valve 24 which is shown in detail in FIGURE 8 and comprises a block 25 having a port 26 adapted for connection to the hydraulic system of the props and a port 27 adapted for connection to the cylinder 23. Communication between the ports 26 and 27 via passages 28 and 29 is controlled by a loading valve 30. Communicating with the passage 28 is a spring-loaded relief or bleed valve 31.

When setting the roof support the pressure fluid flows through the loading valve 30 to the piston and cylinder device 22, 23 which acts on the articulated roof bar 11 to force it against the roof. When the required and predetermined loading has been achieved the loading valve 30 closes. If subsequently the roofing bar or any of the props should require to give or otherwise accommodate themselves to some change in the roof then they can do so because any increase in the load will cause a small amount of hydraulic fluid to be discharged via the bleed valve 31.

It will be appreciated that whilst the chocks have been described as having three legs or props they may have more or less than this number and similarly the intermediate supports may have more or less than two props or legs.

The intermediate supports E and F shown in FIG- URES 5 and 6 serve as double extension hydraulic roof supports and comprise two base members or feet 32 and 33 respectively, which are slidably connected or associated together in side-by-side relationship. Each base member or foot carries the two hydraulic props or legs 12 which are adapted to support a roofing bar 34, 35 at their upper ends.

The foot 32 incorporates a hydraulic ram comprising a cylinder 36 and ram proper 37. Similarly, the foot or base member 33 incorporates a hydraulic ram comprising a cylinder 38 and ram proper 39.

The rams 37 and 39 are linked together as indicated at 40 and 41 by a flexible member (e.g. a wire rope, cord, chain or belt) 42 which runs over an anchorage in the form of a shoe 43 attached, in this particular case, to the coal conveyor C. If the flexible member is in the form of a chain the shoe 43 may be replaced by a chain wheel.

In the position shown in FIGURE 5 it may be assumed that a cut or strip has been made and it is required to advance the roof support E. Firstly then, the conveyor is pushed over by the chocks D as previously described. Due to the anchorage of the rams 37, 39 to the conveyor by the shoe 43 and the flexible member 42, this pushing over of the conveyor will extend the rams to the position shown in FIGURE 5.

The support E is then lowered from the roof, hydraulic pressure supplied to the ram 36, 37 and as a result the foot 32 is advanced into the position 32a shown in dotted lines.

Hydraulic pressure is simultaneously supplied to the ham 38, 39 so that the ram 39 is retracted and as a result the foot 32 is advanced still further, i.e. from the position 32a to the position 32]) shown in chain lines. The support E is then set to support the roof by application of hydraulic pressure to the legs 12.

Following the next cut or strip of the coal face a similar procedure to that just described takes place except that this time the foot F is advanced. Thus, the supports E, F alternately make two steps forwardly following each cut or strip of the coal face and it will be appreciated that this increased advance is achieved without any increase in the length of stroke of the rams and without the rams extending backwards beyond the rear of the support.

It will be understood that the support above described will incorporate valve means, preferably a single selector valve, which provides for the supply and cut-off of pressure fluid to the props and rams and the venting thereof as required.

The roof bar part 35 is articulated to the part 34 at 44 and is provided with a relief and loading valve similar to that described with reference to FIGURES 7 and 8. There are also other features in the intermediate supports similar to features of the chocks and where applicable like reference numerals have been used to designate like parts.

It should be understood that the operating sequence described above is only given by way of example and may be varied. For instance, the rams in the intermediate supports may be used to push over the conveyor.

It will be appreciated that whilst the chocks have been described as having three legs or props they may have more or less than this number and similarly the intermediate supports may have more or less than two props, or legs.

I claim:

1. The combination of a coal conveyor and a walking mine roof support system comprising a plurality of main supports arranged in a row and a plurality of intermediate supports arranged in two rows one row in advance of the other, there being a pair of such intermediate supports one from each row between each pair of main supports, the main supports comprising a base, a canopy, hydraulically extensible prop means mounted on said base and supporting said canopy, and a hydraulic ram in said base extending forwardly from the support whereby said ram is operative to push said conveyor over to the coal face, means securing said ram to the conveyor whereby said ram is operative to advance said base towards the conveyor, each intermediate support comprising a base member, a roofing bar, hydraulically extensible prop means on said base member and supporting said roofing bar, a hydraulic ram in said base member and a flexible member connecting the ram of each intermediate support of one row to the ram of its neighbouring intermediate support of the other row, said flexible member running over an anchorage on the conveyor whereby the rams of the intermediate supports are operative to advance said intermediate supports towards the conveyor two steps at a time.

2. The combination of a coal conveyor and a walking mine roof support system comprising a plurality of main supports arranged in a row and a plurality of intermediate supports arranged in two rows one row in advance of the other, there being a pair of such intermediate supports one from each row between each pair of main supports, the main supports comprising a base, a canopy, hydraulically extensible proper means mounted on said base and supporting said canopy, and a hydraulic ram in said base extending forwardly from the support whereby said ram is operative to push said conveyor over to the coal face, means securing said ram to the conveyor whereby said ram is operative to advance said base towards the conveyor, each intermediate support comprising a base member, a roofing bar, hydraulically extensible prop means on said base member and supporting said roofing bar, a hydraulic ram in said base member and a flexible member connecting the ram of each intermediate support of one row to the ram of its neighbouring intermediate support of the other row, said flexible member running over an anchorage on the conveyor, the hydraulic rams of the main supports, when extended to push the conveyor over towards the coal face, also extending by means of said flexible member, the hydraulic rams of the intermediate supports so that when pressure fluid is supplied to the hydraulic rams of the rearmost row of intermediate supports said row is advanced one step towards the coal face and when hydraulic fluid is supplied to the hydraulic ram of the foremost row said rearmost row of intermediate supports is advanced a further step towards the coal face.

3. The combination of a coal conveyor and a walking mine roof support system comprising a plurality of main supports arranged in a row and a plurality of intermediate supports arranged in two rows one row in advance of the other, there being a pair of such intermediate supports one from each row between each pair of main supports, the main supports comprising a base, a canopy, hydraulically extensible prop means mounted on said base and supporting said canopy, and a hydraulic ram in said base extending forwardly from the support whereby said ram is operative to push said conveyor over to the coal face, means securing said ram to the conveyor whereby said ram is operative to advance said base towards the conveyor, each intermediate support comprising a base member, a roofing bar, hydraulically extensible prop means on said base member and supporting said roofing bar, a hydraulic ram in said base member and a flexible member connecting the ram of each intermediate support of one row to the ram of its neighbouring intermediate support of the other row, said flexible member running over an anchorage on the conveyor whereby the rams of the intermediate supports are operative to advance said intermediate supports towards the conveyor two steps at a time, the intermediate supports having a retractable and extensible roof engaging bar which, when extended, provides immediate cover under newly exposed roof.

4. The combination of a coal conveyor and a walking mine roof support system comprising a plurality of main supports arranged in a row and a plurality of intermediate supports arranged in two rows one row in advance of the other, there being a pair of such intermediate supports one from each row between each pair of main supports, the main supports comprising a base, a canopy, hydraulically extensible prop means mounted on said base and supporting said canopy, and a hydraulic ram in said base extending forwardly from the support whereby said ram is operative to push said conveyor over to the coal face, means securing said ram to the conveyor whereby said ram is operative to advance said base towards the conveyor, each intermediate support comprising a base member, a roofing bar, hydraulically extensible prop means on said base member and supporting said roofing bar, a hydraulic ram in said base member and a flexible member connecting the ram of each intermediate support of one row to the ram of its neighbouring intermediate support of the other row, said flexible member running over an anchorage on the conveyor, the hydraulic rams of the main supports, when extended to push the conveyor over towards the coal face, also extending, by means of said flexible member, the hydraulic rams of the intermediate supports so that when pressure fluid is supplied to the hydraulic rams of the rearmost row of intermediate supports said row is advanced one step towards the coal face and when hydraulic fluid is supplied to the hydraulic ram of the foremost row said rearmost row of intermediate supports is advanced a further step towards the coal face, the intermediate supports having a retractable and extensible roof engaging bar which, when extended, provides immediate cover under newly exposed roof.

5. In combination with a coal conveyor, a self-advancing mine roof support located on one side of said conveyor and comprising two support members positioned in side-by-side relationship and movable independently towards the conveyor and each having hydraulically extensible prop means whereby it can be secured between floor and roof, a pair of hydraulic ram cylinders, means securing one of said ram cylinders to each of said support members, a ram proper working in each of said ram cylinders and directed for movement towards and away from said conveyor, an anchorage on the conveyor opposite said rams proper, and a flexible member connecting the two rams proper together and looped around said anchorage and having a length equal to the distance from the forward ends of the rams proper extending about the anchorage.

6. In combination with a coal conveyor, a self-advancing mine roof support located on one side of said conveyor and comprising two support members positioned in side-by-side relationship for independent movement towards said conveyor and each having hydraulically extensible prop means whereby it can be secured between floor and roof, a pair of hydraulic ram cylinders, means securing one of said ram cylinders to each of said support members, a ram proper working in each of said ram cylinders and directed for movement towards and away from said conveyor, a sheave pivotally supported on the conveyor opposite said rams, and a flexible member connecting the two rams proper together and looped around said sheave and having a length equal to the distance from the forward ends of the rams proper extending about the sheave.

7. In combination with a coal conveyor, a self-advanc- 7 ing mine roof support located on one side of said conveyor and comprising two support members eachhaving a foot part, at least two hydraulically extensible props mounted on said foot part and extending vertically upwards therefrom, and a roofing bar mounted on said props, a pair of hydraulic ram cylinders, means securing one of said ram cylinders to each of said foot parts, a ram proper Working in each of said ram cylinders and directed for movement towards and away from the conveyor, an anchorage on the conveyor opposite said rams proper, and a flexible member connecting the two rams proper together and looped around said anchorage andhaving a length equal to the distance from the forward ends of the rams proper extending about the anchorage.

References Cited in the file of this patent UNITED STATES PATENTS 2,780,067 Jacobi et al. Feb. 5, 1957 2,795,934 Jenkins June 18, 1957 FOREIGN PATENTS 784,217 Great Britain 1957 804,386 Great Britain 1958 1,201,143 France July 1959 

5. IN COMBINATION WITH A COAL CONVEYOR, A SELF-ADVANCING MINE ROOF SUPPORT LOCATED ON ONE SIDE OF SAID CONVEYOR AND COMPRISING TWO SUPPORT MEMBERS POSITIONED IN SIDE-BY-SIDE RELATIONSHIP AND MOVABLE INDEPENDENTLY TOWARDS THE CONVEYOR AND EACH HAVING HYDRAULICALLY EXTENSIBLE PROP MEANS WHEREBY IT CAN BE SECURED BETWEEN FLOOR AND ROOF, A PAIR OF HYDRAULIC RAM CYLINDERS, MEANS SECURING ONE OF SAID RAM CYLINDERS TO EACH SUPPORT MEMBERS, A RAM PROPER WORKING IN EACH OF SAID RAM CYLINDERS AND DIRECTED FOR MOVEMENT TOWARDS AND AWAY FROM SAID CONVEYOR, AN ANCHORAGE ON THE CONVEYOR OPPOSITE SAID RAMS PROPER, AND A FLEXIBLE MEMBER CONNECTING THE TWO RAMS PROPER TOGETHER AND LOOPED AROUND SAID ANCHORAGE AND HAVING A LENGTH EQUAL TO THE DISTANCE FROM THE FORWARD ENDS OF THE RAMS PROPER EXTENDING ABOUT THE ANCHORAGE. 